• Title/Summary/Keyword: Total chromium

Search Result 160, Processing Time 0.024 seconds

Distribution of Airborne Hexavalent Chromium Concentrations in Large Industrial Complexes in Korea

  • Kang, Byung-Wook;Lee, Hak-Sung;Kim, Jong-Ho;Hong, Ji-Hyung;Kim, Rok-Ho;Seo, Young-Kyo;Han, Jin-Seok;Baek, Kyung-Min;Kim, Min-Ji;Baek, Sung-Ok
    • Asian Journal of Atmospheric Environment
    • /
    • v.10 no.4
    • /
    • pp.208-216
    • /
    • 2016
  • This paper reports the results of a field evaluation which used sampling and analytical methods to determine the levels of airborne hexavalent chromium Cr(VI) in major industrial complexes in Korea over a seven year period (2007-2013). Cr(VI) concentrations were determined using cellulose filter sampling and ion chromatography analysis. In order to validate the analytical performance of these methods, studies were also carried out to investigate data quality control (QC) parameters, such as the method detection limit (MDL), repeatability, and recovery efficiencies. The average concentrations of Cr(VI) for the nine industrial complexes in Korea were in the range of 0.09 to $1.40ng/m^3$, which is similar to of the concentrations in other industrial areas around the world. The impacts of Cr(VI) emissions from industrial areas on Cr(VI) concentrations in neighboring-residential areas were considerably low, and the dispersion of Cr(VI) from industrial areas to residential areas was estimated to be 'not-significant'. Cr(VI) levels were not affected by seasonal variation, which suggests that chromium was emitted continuously from the industrial sources throughout the year. The concentration of Cr(VI) measured accounted for 0.7 to 9.4 percent of the total chromium level, which is a low percentage compared to those in other urban areas around the world. This is the first report in an international journal of a field study conducted in Korea to determine the concentration of Cr(VI) in the ambient air of industrial and residential areas.

Recent updates for biomaterials used in total hip arthroplasty

  • Hu, Chang Yong;Yoon, Taek-Rim
    • Biomaterials Research
    • /
    • v.22 no.4
    • /
    • pp.259-270
    • /
    • 2018
  • Background: Total hip arthroplasty (THA) is probably one of the most successful surgical interventions performed in medicine. Through the revolution of hip arthroplasty by principles of low friction arthroplasty was introduced by Sir John Charnley in 1960s. Thereafter, new bearing materials, fixation methods, and new designs has been improved. The main concern regarding failure of THA has been the biological response to particulate polyethylene debris generated by conventional metal on polyethylene bearing surfaces leading to osteolysis and aseptic loosening of the prosthesis. To resolve these problems, the materials of the modern THA were developed since then. Methods: A literature search strategy was conducted using various search terms in PUBMED. The highest quality articles that met the inclusion criteria and best answered the topics of focus of this review were selected. Key search terms included 'total hip arthroplasty', 'biomaterials', 'stainless steel', 'cobalt-chromium', 'titanium', 'polyethylene', and 'ceramic'. Results: The initial search retrieved 6921 articles. Thirty-two articles were selected and used in the review. Conclusion: This article introduces biomaterials used in THA and discusses various bearing materials in currentclinical use in THA as well as the newer biomaterials which may even further decrease wear and improve THA survivorship.

Simple Semiquantitative Determination and Selective Preconcentration of Trace Heavy Metals in Environmental Pollutants : Determination of Chromium (VI) with DPC Gel (環境汚染 重金屬의 選擇的 濃縮 및 簡易分析法 : DPC 겔의 의한 크롬 (VI) 의 定量)

  • Yong Keun Lee;Kyu Ja Whang;In Hwa Woo
    • Journal of the Korean Chemical Society
    • /
    • v.25 no.4
    • /
    • pp.275-282
    • /
    • 1981
  • A simple semiquantitative procedure was developed for the determination of sub-ppm level of chromium(VI) in aquatic samples by using an analytical micro-column packed with diphenylcarbazide(DPC) gel beads. DPC gel beads were prepared by swelling XAD-2 resin(115∼150 mesh in dry condition) in ethanol for 10min, packing into a glass column(1.5 mm bore, 65nm length) and adsorbing 1ml of ethanol solution of $2{\times}10^{-3}M$ DPC for 20min at room temperature. When 0.5ml of ethanol solution containing chromium(VI) was passed through the DPC gel column for 40min, the original white color of the reagent gel turned to red-violet from the up-stream of the column. As the length of colored band was proportional to the total amount of chromium(VI) in the sample solution passed through the column, the concentration of chromium(VI) could be determined from the calibration line which had been prepared by using the standard solution. Chromium(VI) ion as small as from 0.1 to 0.8 ppm could be determined with ${\pm}5{\sim}{\pm}15{\%}$ relative errors. Since other interfering cations were few, 100-fold excess of Fe(III), 50-fold excess of Cu(II) could be masked with EDTA. This method was successfully applied to the analysis of chromium(VI) in industrial effluents.

  • PDF

A Study of Working Environments and Workers Exposed to Chromium (크롬 취급 사업장의 작업환경 및 근로자 폭로 실태에 관한 연구)

  • Yu, Byung-Chul;Son, Byung-Chul;Jun, Jin-Ho;Han, Yong-Soo;Son, Hye-Sook;Lee, Chae-Eun;Jeong, Woon
    • Journal of Preventive Medicine and Public Health
    • /
    • v.27 no.3 s.47
    • /
    • pp.517-530
    • /
    • 1994
  • For the purpose of providing the basic data for health management of workers who are exposed to chromium and for improving the quality of working environment, the authors evaluated blood and urinary level of chromium, the occupational history. AST, ALT, Hb, Hct, nasal specular examinaton on 287 workers who have been dealed chromium compounds in 56 manufacturing Industries of five types, that is, 38 metal plating services(plating),4 manufacture of other fabricated metal products (fabricated metal product), 5 manufacturing of dyestuff(dyestuff), 6 dressing and dyeing of leather(leather), 3 others(manufacture of pottery and ceramic househod wares, motor vehicles, electronic valves and tubes and other electronic components) and also measured the level of chromium in air from February to October 1993. The results were as follows ; 1. The utilized type of chromium compounds was the hexavalent state in plating fabricated metal product dyestuff, leather and the trivalent state in .other, and atmosperic chromium concentration as geometric mean was $0.0138mg/m^3(0.001{\sim}0.068mg/m^3)$ in plating, $0.0115mg/m^3(0.006{\sim}0.015mg/m^3)$ in fabricated matal product, $0.068mg/m^3(0.002{\sim}0.019mg/m^3)$ in dyestuff, $0.0083mg/m^3(0.002{\sim}0.028mg/m^3)$ in leather $0.0039mg/m^3(0.003{\sim}0.005mg/m^3)$ in other by the type of industry and it exceeded TLV-TWA ($0.05mg/m^3$) in five (13.6%) of plating services. 2. The geometric mean of chromium in blood was $1.54{\mu}g/dl(0.10{\sim}3.62{\mu}g/dl)$ in Plantng, $0.94{\mu}g/dl(0.27{\sim}2.82{\mu}g/dl)$ in fabricated metal product, $0.51{\mu}g/dl(0.10{\sim}3.25{\mu}g/dl)$ in dyestuff, $0.87{\mu}g/dl(0.15{\sim}8.00{\mu}g/dl)$ in leather, $0.55{\mu}g/dl(0.20{\sim}2.28{\mu}g/dl)$ in other by the type of industry(p<0.001). 3. The geometric mean of chromium in urine was $14.47{\mu}g/l(6.90{\sim}28.00{\mu}g/l)$ in planting, $4.63{\mu}g/l(0.24{\sim}43.00{\mu}g/l)$ in fabricated metal product, $5.93{\mu}g/l(1.00{\sim}33.00{\mu}g/l)$ in dyestuff, $11.09{\mu}g/l(0.80{\sim}48.00{\mu}g/l)$ in leather, $12.41{\mu}g/l(10.10{\sim}41.00{\mu}g/l)$ in other by the type of industry(p<0.001). 4. As the result of nasal specular examination, twenty four cases (8.4%) of nasal septal perforation among 287 total subjects was observed, and there were 17 (9.7%) cases in plating, 4 csaes (14.3%) in dressing and dyeing of leather. In the comparison of chromium concentration in blood and urine between the perforated group and non-perforated group, the perforated group showed a significantly higher value as $1.883{\pm}3.055{\mu}g/dl\;and\;0.793{\pm}0.815{\mu}g/dl$(P<0.001), $21.31{\pm}34.610{\mu}g/L\;and\;9.304{\pm}11.079{\mu}g/L$ (P<0.001). 5. The mean concentration of chromium in blood, urine and the mean level of AST, ALT, Hb and Hct in exposure group were higher than those of control group(p<0.001).

  • PDF

Reduction of Hexavalent Chromium Collected on PVC Filters in Field Electroplating Process (현장 도금 공정에서 PVC 여과지에 채취된 6가 크롬의 환원)

  • Shin Yong Chul;Paik Nam Won;Yi Gwang Yong;Lee Byung Kyu;Lee Ji Tae
    • Journal of Environmental Health Sciences
    • /
    • v.28 no.1
    • /
    • pp.41-49
    • /
    • 2002
  • Recently, pilot studies showed an evidence of reduction of airborne hexavalent chromium, Cr(VI), on PVC filter during air sampling and storage. However, the information on this in the field was limited. Thus, we studied the reduction behaviors of airborne Cr(VI) on PVC filters during sampling and storage at three field electroplating operations. Regression between sampling time and the reduction (ratio of Cr(VI) to total Cr concentrations) was not statistically significant (p>0.05). However, the reductions in samples collected for 240 ~ 340 minutes were significantly higher than those for 30 - 60 minutes. On the other hand, another experiment showed a good correlation (r=0.96) between sampling time and the reduction without an exceptional value. Storage temperature was not a factor affecting the reduction of Cr(VI) collected on PVC filter. The loss of Cr(VI) samples stored in alkali solution (2% NaOH/3% Na$_2$CO$_3$) was significantly lower than that stored in vial according to NIOSH method (p<0.05). Thus, dipping Cr(VI) samples into alkali solution was a storage method to minimize tile reduction.

Effect of Chromium Dietary Supplementation on the Immune Response and Some Blood Biochemical Parameters of Transport-stressed Lambs

  • Al-Mufarrej, S.I.;Al-Haidary, I.A.;Al-Kraidees, M.S.;Hussein, M.F.;Metwally, H.M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.21 no.5
    • /
    • pp.671-676
    • /
    • 2008
  • Forty-eight Naemi lambs (avg. BW 31.7 kg) were transported by truck for a distance of 1,450 km from Al-Jouf to Riyadh, Saudi Arabia. On arrival day, the lambs were randomly allocated to four groups receiving diets supplemented with 0.0, 0.3, 0.6 and 0.9 ppm organic chromium (Cr). Each group consisted of four separately housed replicates of three lambs each. The animals were fed ad libitum on a grower diet for 84 days. Blood samples were obtained shortly before transportation, upon arrival and at weekly intervals thereafter from all lambs for analysis of plasma and serum. Plasma glucose and serum cortisol, total protein, albumin, urea-N and total cholesterol concentrations were determined. A cursory clinical examination of the lambs, along with rectal temperature, was undertaken at different intervals during the experiment. The lambs were inoculated each with 2 ml i.v. chicken red blood cells (CRBC) on days 0, 21, and 42. Serum total, IgG and IgM antibody titers were determined at weekly intervals post-immunization. An in vivo intradermal hypersensitivity test was carried out on 6 lambs from each group on days 10 and 70. Transportation of the lambs resulted in a significant (p<0.001) elevation of serum cortisol, total protein and albumin levels, as well as increased plasma glucose concentration, with corresponding decrease in total cholesterol, while blood urea-N remained largely unchanged. These constituents returned to normal levels during subsequent weeks, with no significant differences in their concentrations being observed between the Cr-supplemented groups and controls. Rise in rectal temperature after transportation was reduced to a greater extent (p<0.05) in Cr-supplemented versus control lambs. Total, IgG and IgM antibody titers against CRBC rose significantly (p<0.05) during immunizations in all groups, with significantly and linearly higher (p<0.05) total and IgG titers in Cr-supplemented versus control lambs. By contrast, no significant effect due to Cr supplementation was recorded in IgG titers, which increased equally in Cr-fed and control groups. Skin thickness in response to intradermal inoculation of phytohaemagglutinin (PHA) was also significantly (p<0.01) increased as a result of Cr supplementation. These results indicate that dietary Cr supplementation might be useful during stress especially for enhancing immune responses in transport-stressed lambs.

Effects of Chromium Methionine Supplementation on Blood Metabolites and Fatty Acid Profile of Beef during Late Fattening Period in Holstein Steers

  • Nejad, Jalil Ghassemi;Lee, Bae-Hun;Kim, Byong-Wan;Ohh, Sang-Jip;Sung, Kyung Il
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.29 no.3
    • /
    • pp.378-383
    • /
    • 2016
  • The objective of this study was to determine the effects of chromium methionine (Cr-Met) chelate supplementation on blood metabolites and fatty acid profile of beef from Holstein steers during late fattening period. Fifteen Holstein steers were allotted randomly into two groups including the control (non Cr-Met feeding, NCM, ave. body weight [BW] = $483{\pm}25.7kg$) and the treatment (Cr-Met feeding for 4 months, 4CM, ave. $BW=486{\pm}27.5kg$) group. The feeding amount of Cr-Met to animals was limited to 400 ppb/cow/d and was supplemented to total mixed ration. No difference in blood albumin, alkaline phosphatase, urea-nitrogen, calcium, creatine, glucose, total protein, triglyceride, and cholesterol were observed between the treatment groups (p>0.05). The level of high density lipoprotein was higher in the 4CM group than the NCM group, whereas low density lipoprotein was lower in the 4CM group (p<0.05). The fatty acid composition (caprate, laurate, myristate, pentadecanoate, palmitate, palmitoleate, margarate, cis-11 heptadodecanoate, stearate, oleate, trans-vaccenate, linoleate, cis-11 eicosenoate, docosa hexaenoic acid, and docosa pentaenoic acid) of the beef showed no difference between the two groups (p>0.05). The arachidonic acid level tended to be higher in the 4CM than the NCM group (p = 0.07). Cr-Met had no influence (p>0.05) on the ratio of saturated, unsaturated, unsaturated/saturated, monounsaturated/saturated and polyunsaturated/saturated fatty acids whereas the ratio of polyunsaturated fatty acids (PUFA) in the 4CM group was comparatively higher than the NCM group (p<0.05). This study concluded that feeding Cr-Met supplementation in 400 ppb/d to Holstein steers for 4 months during late fattening period can improve some blood metabolites and beef quality by increasing PUFA and gamma-linoleate compositions of beef.

Assessment of Tribological Characteristics of CoCrW and CoCrMo Alloys (CoCrW와 CoCrMo 합금의 트라이볼로지 특성 평가)

  • Kwon, Dong-Gyun;Oh, Se-Jin;Chung, Koo-Hyun
    • Tribology and Lubricants
    • /
    • v.38 no.4
    • /
    • pp.162-169
    • /
    • 2022
  • Cobalt-chromium (CoCr)-based alloys have been used for wear applications because of their excellent mechanical properties and wear resistance. With growing concern over environmental problems, CoCr alloys are expected to be used for various tribological applications in degraded lubrication states. To expand the applicability of the materials, data should be accumulated across a broad spectrum of experimental parameters. In this work, the friction and wear characteristics of cobalt-chromium-tungsten (CoCrW) and cobalt-chromium-molybdenum (CoCrMo) alloys are investigated experimentally. The tests are conducted using a pin-on-reciprocating-plate tribotester in dry lubrication. CoCrW and CoCrMo are used as pin and plate materials to investigate the effect of the counter material. The results show that the friction coefficients between CoCrW and CoCrMo generally range from 0.4 to 0.5. The friction coefficient between the CoCrW pin and plate is found to be slightly small. However, the total wear between the CoCrW pin and plate is found to be the largest. In contrast, the total wear between the CoCrW pin and plate is relatively small. Furthermore, CoCrW may cause a faster wear progression of CoCrMo, especially for the case in which CoCrMo is used as the pin material. The results of this work provide a better understanding of the tribological properties of CoCrW and CoCrMo alloys. In addition, this work provides a practical guideline for the use of CoCrW and CoCrMo from the tribological design viewpoint.

Effects of supplemental different clay minerals in broiler chickens under cyclic heat stress

  • Jaewoo An;Jihwan Lee;Minho Song;Hanjin Oh;Yongju Kim;Seyeon Chang;Youngbin Go;Dongcheol Song;Hyunah Cho;Haeryoung Park;Hyeun Bum Kim;Jinho Cho
    • Journal of Animal Science and Technology
    • /
    • v.65 no.1
    • /
    • pp.113-131
    • /
    • 2023
  • The objective of this study was to investigate the effect of supplementing clay minerals and organic chromium in feed on broiler chicken under heat stress (HS). A total of 90 one-day-old broiler chicken (Arbor Acres) with an initial body weight of 45.0 ± 0.2 g were assigned to five treatment groups (six replications, three birds each cage): 1) NC group, basal diet under room temperature environment; 2) PC group, basal diet under high temperature (HT) environment; 3) ILT group, basal diet + 1% illite + HT; 4) ZLT group, basal diet + 1% zeolite + HT; 5) OC group, basal diet + 400 ppb/kg organic chromium + HT. The ILT and ZLT groups had significantly higher body weight than the PC group in 4 weeks. Apparent total tract digestibility of gross energy was increased in the ILT, ZLT, and OC groups compared to the PC group. The NC group had lower foot-pad dermatitis score than other groups. Escherichia coli population in the cecum and feces was decreased in the ZLT group than in the PC group. Lactobacillus in cecum and feces was significantly increased in the ZLT group than in the PC group. Regarding blood profiles, blood cortisol was decreased in the NC and ILT groups compared to the PC group. Water holding capacity and pH were increased in the ZLT group than the PC group. In conclusion, according to the results of growth performance, nutrients digestibility, bacteria counts, and meat characteristics, supplementation of the ZLT in broiler diet can alleviate HS.

Effects of Dietary Chromium Picolinate Supplementation on Growth Performance and Immune Responses of Broilers

  • Lee, Der-Nan;Wu, Fu-Yu;Cheng, Yeong-Hsiang;Lin, Rong-Shinn;Wu, Po-Ching
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.16 no.2
    • /
    • pp.227-233
    • /
    • 2003
  • Two experiments were conducted to evaluate the effects of chromium (Cr) on the growth performance, bone trait, serum traits, and immune responses in broilers. The broilers were fed corn-soybean meal basal diet supplemented with Cr at level of 0(control), 200, 400, or 800 ppb in the form of chromium picolinate (CrPic). The broilers were fed treated diets for 6 weeks in Exp. 1, but the Cr supplement was removed for the last 3 weeks in Exp. 2. Exp. 1 showed that dietary supplement of Cr did not affect growth performance of the broiler, though improved feed efficiency (p<0.05) was observed during 0 to 3 weeks. Moreover, serum total (p<0.05) and HDL cholesterols (p<0.06) were significantly higher in pooled Cr added group at 6 weeks of age, however, the difference was not significant in Exp. 2. The pooled Cr added group in Exp.1 had significantly lower (p<0.05) alkaline phosphatase activity and higher (p<0.09) calcium at 3 weeks. Significantly lower phosphorus was also observed in Exp. 2. With continued supplement of Cr as in Exp. 1, the alkaline phosphatase activity maintained higher at 6 weeks, as opposed to significantly lower in Exp. 2, which had no further Cr supplement. Higher bone breaking strength was observed in 400 ppb Cr supplemented in Exp. 1, though not significantly different. Serum glucose and triglyceride were not affected by Cr supplement. Antibody against Infectious Bronchitis (IB) was significantly (p<0.05) higher with 400 ppb Cr supplemented, and anti-Newcastle disease (ND) antibody also tended to be higher (p<0.06) in pooled Cr added group at 6 weeks of age in Exp. 1. Peripheral blood blastogenesis activity was not different among the treatments. The results suggest that diet supplemented with 400 ppb CrPic may be beneficial to the broiler.